Channel bus splice assembly

ABSTRACT

For use in switchgear equipment having channel bus bars joined together at a bus joint, there is provided a channel bus splice assembly and method. The channel bus splice assembly comprises switchgear or switchboard equipment having channel bus bars joined together at a bus joint, there is provided a channel bus splice assembly. The channel bus splice assembly comprises an inner splice plate defining a plurality of throughbores. A sliding clamp plate is configured to reciprocally move within the inner splice plate. The sliding clamp plate defines a plurality of access ports. A pair of nut plates is coupled to the sliding clamp plate and having threaded orifices corresponding to selected throughbores in the inner splice plate. An outer splice plate having a plurality of throughbores corresponding to the threaded orifices in the nut plates.

BACKGROUND

The present invention relates generally to the field of electricalswitchboards and panel boards having bus bars, and more particularly toa channel bus splice assembly for use in switchgear and switchboardequipment.

Switchgear assemblies, switchboards and panelboards are general termswhich cover metal enclosures, housing switching and interrupting devicessuch as fuses, and circuit breakers, along with associated control,instrumentation and metering devices. Such assemblies typically includeassociated bus bars, interconnections and supporting structures used forthe distribution of electrical power. Low voltage switchgear andswitchboards operate at voltages up to 600 volts and with continuouscurrents up to 5000 amps or higher. Such devices are also designed towithstand short circuit currents ranging up to 200,000 amps (3 phase rmssymmetrical).

Typical switchgear equipment is composed of a lineup of several metalenclosed sections. Each section may have several circuit breakersstacked one above the other vertically in the front of the section witheach breaker being enclosed in its own metal compartment. Each sectionhas a vertical or section bus which supplies current to the breakerswithin the section via short horizontal branch buses. The vertical busbars in each section are supplied with current by a horizontal main busbar that runs through the lineup of metal enclosed sections. A typicalarrangement includes bus bars for each electrical phase of a multiplephase system which may include three power phases and a neutral.

The bus bars typically are joined by bus bar joints, also referred to assplice, in the switchgear switchboard line-up. Bus bar splices typicallyare assembled with bolts that must be accessible for routinemaintenance, for example, tightening or replacing bus bars. Bus barassemblies typically increase in thickness as the current rating of theswitchgear equipment increases. It is also typical to provide insulationof various components within a switchgear or switchboard enclosureincluding a cover of the bus bar splices.

Thus, there is a need for a bus bar splice assembly for use inswitchgear equipment that will allow maintenance of a bus bar splice.There is a further need for a bus joint splice assembly that providesaccess to the fasteners. There is an additional need for a bus bar coverassembly that can accommodate various current ratings (sizes) of bus barjoint.

SUMMARY

For use in switchgear equipment having channel bus bars joined togetherat a bus joint, there is provided a channel bus splice assembly. Thechannel bus splice assembly comprises an inner splice plate defining aplurality of throughbores. A sliding clamp plate is configured toreciprocally move within the inner splice plate. The sliding clamp platedefines a plurality of access ports. A pair of nut plates are coupled tothe sliding clamp plate and having threaded orifices corresponding toselected throughbores in the inner splice plate. An outer splice platehaving a plurality of throughbores corresponding to the threadedorifices in the nut plates.

There is also provided a method of connecting first and second channelbus bars in a switchgear assembly with a channel bus splice assembly.The method comprises the steps of installing an inner splice plate of achannel bus splice assembly between flanges of the channel bus bars.Coupling the inner splice plate to one of the channel bus bars withinterior fasteners. Coupling a pair of nut plates to a sliding clampplate. Installing the sliding clamp plate in the interior splice plate,with the sliding clamp plate configured to reciprocally move within theinner splice plate and defining a plurality of access ports. Mounting anouter splice plate having throughbores with exterior fasteners, theexterior fastener is configured to pass through the throughbores in theouter splice plate and thread into the nut plates wherein the secondchannel bus bar is coupled between the outer splice plate and the innersplice plate.

There is also provided a method of servicing and maintaining a channelbus splice assembly connecting first and second channel bus bars in aswitchgear assembly. The channel bus splice assembly includes aplurality of interior fasteners and a plurality of exterior fasteners,an interior splice plate, a sliding clamp plate having nut plates and anouter splice plate. The method comprises the steps of removing theexterior fasteners from the nut plates. Removing the outer splice plate.Moving the sliding clamp plate to one side until it stops, whereinaccess to some of the interior fasteners is obtained. Manipulating someof the interior fasteners. Moving the sliding clamp plate to the otherside until it stops, wherein access to other of the interior fastenersis obtained. Manipulating other of the interior fasteners. Remountingthe outer splice plate by passing the exterior fasteners through theouter splice plate and threading into the nut plates. The method canalso include the steps of removing and reinstalling a bus joint coverand the step of replacing a member of the channel bus bar. The methodcan also include the step of manipulating one of torquing the fastenersand replacement of the fasteners.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a partial, multiple phase switchgearequipment assembly including an exemplary embodiment of a channel bussplice assembly.

FIG. 2 is a perspective view of an exemplary embodiment of a channel busjoint assembly having a sliding clamp plate in a centered position withexterior fasteners installed.

FIG. 3 is a perspective view of the channel bus bar joint assemblyillustrated in FIG. 2 with the sliding clamp plate positioned to theleft wherein access to the two right side interior fasteners isobtained.

FIG. 4 is a perspective view of the channel bus joint assemblyillustrated in FIG. 2 with the sliding clamp plate positioned to theright wherein access to the two left side interior fasteners isobtained.

FIG. 5 is a perspective view of a partial multiple phase switchgearassembly including an exemplary embodiment of a channel bus spliceassembly illustrating two splice assemblies with exterior fasteners andouter splice plates removed for maintenance, and illustrating atelescoping insulating cover on a channel bus splice assembly.

FIG. 6 is an illustration of an exemplary embodiment of an outer spliceplate with a plurality of thorughbores.

FIG. 7 is an illustration of an exemplary embodiment of an interiorsplice plate having a plurality of throughbores and spring pins placedat pre-selected points a distance (D) apart.

FIG. 8 illustrates several views of an exemplary embodiment of a slidingclamp plate coupled to two nut plates, each nut plate having a pluralityof threaded orifices.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Before describing exemplary embodiments of a bus joint cover assembly30, several comments are appropriate. Switchgear assemblies andswitchboard assemblies typically include vertical (section) bus bar 12and horizontal bus bars 20 to distribute power within the assemblies.Bus bars can be flat and have a rectangular cross-section or bus barscan be C-shaped or U-shaped channels.

A C-shaped or U-shaped channel bus 16 resists bending and twisting inshort-circuit current conditions and is stronger than a flat bar ofcomparable thickness. Further, the channel bus assembly can use one ormultiple bars per phase thereby increasing the current density availablein the system (See FIG. 1). In the multi-channel bus bar system, a firstchannel bus bar 18 and a second channel bar 19, each having flanges 17are aligned with the flanges 17 facing each other as shown in FIGS. 1, 2and 5. Also, inner channels can be nested inside the outer channels ofeach first and second channel bar of each phase. Since variousconfigurations of bus bars can be used, a bus bar splice assembly thatcan be configured to accommodate such various configurations will beadvantageous. A telescoping capability of an insulating splice coverallows the same cover to work with bus bars of varying thickness. Theuse of channel bus bars and the channel bus splice assembly provideshigh short-circuit withstand capability with substantially less bracingthan other geometries.

Referring now to FIG. 1, there is illustrated a portion of a typical,three phase (PH-A, PH-B, PH-C) high current, insulated switch gear busassembly 10. The vertical bus bars 12 (also referred to as section bus)are shown with optional insulating barriers 14 installed. The horizontalbus bars 20 are shown without an optional insulation sleeve. Thehorizontal bus bar joints 25 can be enclosed by a bus joint coverassembly 58 that may telescope in size.

In switchgear equipment 10, utilizing channel bus bars, a typicalarrangement is to utilize multiple channel bus bars. Typically there isan outer bus bar, herein referred to as first channel bus bar 18, and aninterior channel bus bar, herein referred to as second channel bus bar19. The first and second channel bus bars 18, 19 also typically arecomprised of multiple members mounted end-to-end as illustrated in FIGS.1 and 5. The end-to-end configuration together with the flange facingconfiguration of the first and second channel bus bars 18, 19necessitates the use of a channel bus splice assembly 30. The channelbus splice assembly 30 can also be used with a single channel bus bar.In such arrangement, shim plates can be used to align the equipment. Thechannel bus splice assembly 30 includes an inner splice plate 32, asliding clamp plate 40, a pair of nut plates 46 and an outer spliceplate 50. See FIGS. 6-8.

The inner splice plate 32 is configured to fit between the flanges 17 ofthe channel bus bars 18, 19. The inner splice plate 32 defines aplurality of through bores 34 through which fasteners are inserted tosecure the channel bus bars. (See FIG. 7.) The inner splice plate 32 isprovided with pre-selected points 36 which define the distance ofmovement D for the sliding clamp plate 40. A pair of spring pins (alsoreferred to as roll pins) can be set at such pre-selected points 36 toact as stops for the sliding clamp plate 40 by selectively abutting thefeet 44 configured on the sliding clamp plate 40.

A sliding clamp plate 40 is configured to reciprocally move within theinner splice plate 32. The sliding clamp plate 40 defines a plurality ofaccess ports 42 the function of which will be explained below. Thesliding clamp plate 40 can be an angle plate configured with two spacedapart feet 44 which function to stop movement of the sliding clamp plate40 at pre-selected points 36 within the inner splice plate 32.

A pair of nut plates 46 are coupled to the sliding clamp plate 40 andhave threaded orifices 48 corresponding to selected through bores in theinner splice plate 32. The nut plates 46 are coupled to the slidingclamp plate 40 by fasteners, for example, spring pins or rivets ofsuitable size and strength for their intended use. (See FIG. 8.) The nutplates 46 could also be welded to the sliding clamp plate 40 orintegrally formed with the sliding clamp plate 40 during fabrication.

The outer splice plate 50 has a plurality of through bores 52 whichcorrespond to the threaded orifice 48 in the nut plates 46. (See FIG.6.)

The various components of the channel bus splice 30 can be composed ofmetal of suitable composition and compatibility and strength with thechannel bus bars 18, 19, for example copper and aluminum.

It should be noted that mounting holes in the first and channel bus bars18, 19 are aligned on the same axis and have identical hole patterns.This allows for commonality of parts. The several through bores 34, 52and threaded orifices 48 identified above are also configured to alignon the same axis as the mounting holes in the several channel bus bars18, 19. A first selection of fasteners 54 are configured to pass throughthe axis ports 42 and insert into the through bores 34 of the innersplice plate 32 wherein the inner splice plate 32 is secured to achannel bus bar 19 and a second selection of fasteners 56 are configuredto pass through the through bores 52 in the outer splice plate 50 andthread into the nut plates 46 wherein another channel bus bar 18 iscoupled between the outer splice plate 50 and the inner splice plate 32.

Referring now to FIGS. 2, 3 and 4, there is illustrated an exemplaryembodiment of a channel bus splice 30. A method of connecting a firstand second channel bus bar 18, 19 in a switchgear assembly 10 with achannel bus splice assembly 30 will be described. Each channel bus barincludes two end-to-end members. For clarity purposes, only one memberof each channel bus bar 18, 19 is illustrated in FIG. 2 so that thechannel bus splice assembly 30 can be seen.

The method comprises the steps of installing an inner splice plate 32 ofa channel bus splice assembly 30 between the flanges 17 of the channelbus bars 18 and 19. Coupling the inner splice plate 32 to one of thechannel bus bars 19 with interior fasteners 54. Coupling a pair of nutplates 46 to a sliding clamp plate 40 and installing the sliding clampplate 40 in the inner splice plate 32. The sliding clamp plate 40 isconfigured to reciprocally move within the inner splice plate 32 anddefine a plurality of access ports 42. Then mounting an outer spliceplate 50, the plate having through bores 52, with an exterior fastener56. The exterior fasteners 56 are configured to pass through the throughbores 52 in the outer splice plate 50 and thread into the nut plates 46wherein another channel bus bar 18 is coupled between the outer spliceplate 50 and the inner splice plate 32.

FIG. 2 illustrates an internal view of the inner splice plate 32 and thesliding clamp plate 40 in an assembled position between the first andsecond channel bus bars 18 and 19 with the exterior fasteners threadedinto the nut plates 46. The sliding clamp plate 40 is positioned withthe spring pins in the pre-selected points 36 aligned an equal distancebetween the feet 44 of the sliding clamp plate 40.

FIG. 3 illustrates the sliding clamp plate 40 moved to one side of theinner splice plate 32 to the point where one of the spring pins 36 abutsagainst one of the feet 44 of the sliding clamp plate 40. Such alignmentallows access to the two interior fasteners 54 through the access ports42 to fasten the inner splice plate 32 to the interior channel bus bar19. The upper interior fasteners 54 are accessible through the outer busbar plate 50, the inner splice plate 32 and between the nut plates 46.The lower interior fasteners 54 are accessible through the outer bus barplate 50, the inner splice plate 32, between the nut plates 46 andthrough an access port 42 in the sliding clamp plate 40. The diametersof the various through bores and distances between components areconfigured to provide clearance for a fastener and the tool used totorque the fasteners.

FIG. 4 illustrates the sliding clamp 32 moved to the other selectedpoint 36 identified by the spring pin which is a pre-determined distanceD between the feet 44 of the sliding clamp plate 40. Such positionallows access to the two interior fasteners 54 on the right side of thechannel bus splice assembly 30. The upper right interior fastener 54 isaccessible through the outer bus bar 50, the inner bus plate 32 andbetween the nut plates 46. The lower right fastener is accessiblethrough the outer bus plate 50, the inner splice plate 32, between thenut plates 46 and through an access port 42 in the sliding clamp plate40, similarly as described above. In one embodiment, the interior 54 andexterior fasteners 56 are configured alike. In another embodiment theinterior fasteners 54 and the exterior fasteners 56 are configureddifferently to accommodate different tool clearances.

An advantage of the present channel bus splice assembly 30 is that thechannel bus bars 18 and 19 do not have to be completely removed in orderto gain access to and torque the fasteners in the interior channel busbar 19. The method of servicing and maintaining a channel bus spliceassembly 30 for connecting a first and second channel bus bar 18, 19 ina switchgear assembly 30 is hereby disclosed. Each channel bus bar 18,19 may include two end-to-end members. The channel bus splice assembly30 includes a plurality of interior fasteners 54 and a plurality ofexterior fasteners 56, an interior splice plate 32, a sliding clampplate 40 having nut plates 46 and an outer splice plate 50. (Suchcomponents are described above.) The method comprises the steps ofremoving the exterior fasteners 56 from the nut plates 46 and removingthe outer splice plate 50. Moving the sliding clamp plate 40 to one sideof the inner splice plate 32 until it stops, wherein access to some ofthe interior fasteners 54 is obtained and manipulating some of theinterior fasteners 54. Manipulating can include torqueing the fastenerseither to tighten or loosen the fastener and replacement of the fastenerin the event that it is broken, stripped or otherwise damaged. Movingthe sliding clamp plate 40 to another side of the inner splice plate 32until it stops, wherein access to other of the interior fasteners 54 isobtained. Manipulating the other of the interior fasteners 54 andremounting the outer splice plate 50 by passing the exterior fasteners56 through the outer splice plate 50 and threading the fasteners 56 intothe nut plates 46.

The channel bus splice assembly 30 may be provided with an insulatingcover 58 that must be removed before servicing or maintaining thechannel bus splice assembly 30 and then reinstalled the cover 58 uponcompletion of such servicing and maintenance. During such operation, achannel bus bar member may be replaced in the event it is damaged orotherwise requiring service.

While the embodiments illustrated in the figures and described above arepresently disclosed, it should be understood that these embodiments areoffered by way of example only. The channel bus bar splice assembly isnot intended to be limited to any particular embodiment, but is intendedto extend to various modifications that nevertheless flow within thescope of the intended claim. For example, the channel bus bar spliceassembly can be used on vertical bus bars. Other modifications will beevident to those will ordinary skill in the art.

1. A channel bus splice assembly for use in switchgear equipment havingchannel bus bars, the channel bus splice assembly comprising: an innersplice plate, defining a plurality of through bores; a sliding clampplate configured to reciprocally move within the inner splice plate, thesliding clamp plate defining a plurality of access ports; a pair of nutplates coupled to the sliding clamp plate and having threaded orificescorresponding to selected through bores in the inner splice plate; andan outer splice plate having a plurality of through bores correspondingto the threaded orifices in the nut plates.
 2. The channel bus spliceassembly of claim 1, wherein the sliding clamp plate is an angle plateconfigured with two spaced apart feet which stop movement of the slidingclamp plate at pre-selected points within the inner splice plate.
 3. Thechannel bus splice assembly of claim 2, wherein a pair of spring pinsmounted in the inner splice plate contact the feet to define thedistance of movement of the sliding clamp plate.
 4. The channel bussplice assembly of claim 1, wherein the inner splice plate is configuredto mount between the channel bus bars.
 5. The channel bus spliceassembly of claim 1, including a first selection of fasteners configuredto pass through the access ports and insert into corresponding throughbores of the inner plate wherein the inner plate is secured to a channelbus bar and a second selection of fasteners configured to pass throughthe through bores in the outer splice plate and thread into the nutplates wherein another channel bus bar is coupled between the outersplice plate and inner splice plate.
 6. The channel bus splice assemblyof claim 5, wherein the first selection and second selection offasteners are configured alike.
 7. The channel bus splice assembly ofclaim 1, including an insulating cover.
 8. A method of connecting firstand second channel bus bars in a switchgear assembly with a channel bussplice assembly, the method comprising the steps of: installing an innersplice plate of a channel bus splice assembly between flanges of thechannel bus bars; coupling the inner splice plate to one of the channelbus bar with interior fasteners; coupling a pair of nut plates to asliding clamp plate; installing the sliding clamp plate in the innersplice plate, with the sliding clamp plate configured to reciprocallymove within the inner splice plate and defining a plurality of accessports; and mounting an outer splice plate having through bores withexterior fasteners, said exterior fasteners configured to pass throughthe through bores of the outer splice plate and threaded into the nutplates wherein another channel bus bar is coupled between the outersplice plate and inner splice plate.
 9. The method of claim 8, includingthe step of stopping movement of the sliding clamp plate at pre-selectedpoints within the inner splice plate.
 10. The method of claim 9, whereinthe sliding clamp plate an angle plate configured with two spaced apartfeet and a pair of spring pins mounted on the inner splice plate andaligned to contact the feet at the pre-selected points.
 11. The methodof claim 8, wherein the interior and exterior fasteners are configuredalike.
 12. The method of claim 8, including the step of replacing amember of one of the channel bus bars.
 13. The method of claim 8,including the step of covering the channel bus splice assembly.
 14. Themethod of claim 13, wherein a telescoping bus joint cover assembly isused to cover the channel bus splice assembly.
 15. A method of servicingand maintaining a channel bus splice assembly connecting first andsecond channel bus bars in a switchgear assembly, with the channel bussplice assembly including a plurality of interior fasteners and aplurality of exterior fasteners, an inner splice plate, a sliding clampplate having nut plates and an outer splice plate, the method comprisingthe steps of: removing the exterior fasteners from the nut plates;removing the outer splice plate; moving the sliding clamp plate to oneside until it stops, wherein access to some of the interior fasteners isobtained; manipulating some of the interior fasteners; moving thesliding clamp plate to another side until it stops, wherein access toother of the interior fasteners is obtained; manipulating other of theinterior fasteners; and remounting the outer splice plate by passing theexterior fasteners through the outer splice plate and threading into thenut plates.
 16. The method of claim 15, including the steps of removinga bus joint cover and reinstalling the bus joint cover.
 17. The methodof claim 15, wherein the step in manipulating includes one of torque andreplacement of the fastener.
 18. The method of claim 15, including thestep of replacing a member of channel bus bar.